BotW Archer Link
Bow weapons, food, and materials
BotW Horse Rider Link
Horse saddle, food, and sometimes rare weapons
Super Smash Bros Link
Epona, food, and rarely Twilight Princess Link costumes or weapons
Twilight Princess Wolf Link
Wolf Link shows up as an ally to fight alongside you!
8-Bit Link
Smashable barrels full of food and rupees, occasionally costumes and weapons
Ocarina of Time Link
Raw meat, OOT costumes and weapons
Wind Waker or Toon Link
Fish, Wind Waker armor, or Wind Waker tools
BotW Zelda
The Hylian Shield, cooking material
Wind Waker Zelda
Cooking material, random shields (including the Hero's Shield)
Smash Bros Zelda and Sheik
Cooking materials, crafting materials, rare weapons, rarely Sheik's Mask and Twilight Bow
BotW Guardian
Rare weapons and items, occasionally powerful arrows, food
BotW Bokoblin
Club weapons and meat
Smash Bros Ganondorf
Cooking materials and rare weapons -- including the Sword of the Six Sages.
You can unlock Amiibo content multiple times per toy, but only once a day. So if you're itching to take down Calamity Ganon with his own weapons (if possibly from another timeline), pace yourself. It might take a few tries.